XAB Measurements - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 12th April 2006, 04:48 PM   #1
DarkOne is offline DarkOne  Slovakia
diyAudio Member
 
DarkOne's Avatar
 
Join Date: Oct 2001
Location: Bratislava
Default XAB Measurements

Hi All,
This is an update to my previous thread about my amplifier. Description can be found in this thread
Measurements were taken with sound card ESI Juli@.
Feel free to comment.

I forgot to mention that I named amplifier XAB because it runs in heavily biased class AB and uses Pass' X patent.

So, I'll start with spectrum of 1kHz sinewave to 10ohm (couldn't find other power resistor at home) at 5W

Attached Images
File Type: jpg 1ksin_5w_fft.jpg (63.4 KB, 957 views)
  Reply With Quote
Old 12th April 2006, 04:49 PM   #2
DarkOne is offline DarkOne  Slovakia
diyAudio Member
 
DarkOne's Avatar
 
Join Date: Oct 2001
Location: Bratislava
1kHz 35W
Attached Images
File Type: jpg 1ksin_25w_fft.jpg (62.4 KB, 852 views)
  Reply With Quote
Old 12th April 2006, 04:51 PM   #3
DarkOne is offline DarkOne  Slovakia
diyAudio Member
 
DarkOne's Avatar
 
Join Date: Oct 2001
Location: Bratislava
1kHz square wave to 10ohm parael with 1uF capacitor at 25W
Attached Images
File Type: jpg 1ksqr_25w_10r_1u.jpg (38.3 KB, 798 views)
  Reply With Quote
Old 12th April 2006, 04:52 PM   #4
DarkOne is offline DarkOne  Slovakia
diyAudio Member
 
DarkOne's Avatar
 
Join Date: Oct 2001
Location: Bratislava
10kHz square wave at 25W to 10ohm and 1uF parael

Please note that also output from sound card is not perfect, but I hope this is enoug.
Attached Images
File Type: jpg 10ksqr_25w_10r_1u.jpg (43.4 KB, 783 views)
  Reply With Quote
Old 12th April 2006, 06:00 PM   #5
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
That's really excellent.

  Reply With Quote
Old 13th April 2006, 05:07 AM   #6
DarkOne is offline DarkOne  Slovakia
diyAudio Member
 
DarkOne's Avatar
 
Join Date: Oct 2001
Location: Bratislava
Quote:
Originally posted by Nelson Pass
That's really excellent.


Thanks a lot
  Reply With Quote
Old 13th April 2006, 07:26 PM   #7
flg is offline flg  United States
diyAudio Member
 
flg's Avatar
 
Join Date: Jul 2005
Location: North East
Yes, Congrats. I remember the original post and the amp. I have the pics in my "Class A" folder. I liked this design. I remember N.P. made a good comment or two back then also. Happy to here it's working out well for you. Keep it up!
  Reply With Quote
Old 14th April 2006, 08:58 AM   #8
DarkOne is offline DarkOne  Slovakia
diyAudio Member
 
DarkOne's Avatar
 
Join Date: Oct 2001
Location: Bratislava
Thanks flg

I have few modifications prepared for the final version (amp is still in prototype stage). So I hope the amp will be even better.

1st - I'll try to cascode input diff. transistors. According to simulations, it can reduce higher order THD components. Also PSRR should be better. If not, I can eliminate it from PCB without much modifications.

2nd - These measurements were taken from amplifier, which did not use degeneration resistors on sources of diff pairs. I'm going to use 47R. If there's no success, I can bypass them anytime.

3rd - Currently every chanel is on 3 PCBs wired together with ribbon cable (practical, but not reliable). One chanel already damaged due to wrong connection. So new version (final one, I hope) will be on 1 PCB to avoid problems.

I'll post complete schematics with component values and PCB layout in few months, stay tuned.
  Reply With Quote
Old 14th April 2006, 07:03 PM   #9
flg is offline flg  United States
diyAudio Member
 
flg's Avatar
 
Join Date: Jul 2005
Location: North East
Yes, I tend to have a few proto boards to many by the time something works good...
Earlier you commented on your measurement set, ESI Juli@ sound card ??? Could you elaborate. I have some equipment but I just rcently downloaded some software (RTA & RMAA) for use on my E-MU card. I was initially impressed. But I deceided I needed to vacuum the floor before crawling around doing the cable thing. Well, I must have bumped the putor with the vacuum because I lost a chunk of the OS on disc and had to rebuild the putor with a few new components...
Yes, The Amp, another alternative to more components might be to raise the voltage as high as possible. Basically, the curve gets bigger but the swing stays the same and is little more linear. Just an idea.
If you run a BOSOZ at + & - 100V it works even better!
  Reply With Quote
Old 14th April 2006, 08:56 PM   #10
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
DarkOne,

do you really find it excellent?

Regards,
Pavel
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
hi vi measurements blue934 Multi-Way 20 23rd August 2009 05:21 PM
New T-Amp measurements Pano Class D 12 14th March 2006 11:32 AM
SW measurements Grandma´s_SUB Everything Else 9 10th January 2005 01:34 PM
anyone have measurements of TB 871? morbo Multi-Way 5 27th November 2004 03:10 AM
Some CCS measurements Jocko Homo Solid State 10 29th May 2002 12:54 PM


New To Site? Need Help?

All times are GMT. The time now is 02:58 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2